Effect of ring rotation upon gas adsorption in SIFSIX-3-M (M = Fe, Ni) pillared square grid networks

<div>Disordered metal–organic frameworks are emerging as an attractive class of functional materials, however their applications in gas storage and separation have yet to be fully explored. Here, we investigate gas adsorption in the topologically disordered Fe-BTC framework and its crystalline counterpart, MIL‑100. Despite their similar chemistry and local structure, they exhibit very different sorption behaviour towards a range of industrial gases, noble gases and hydrocarbons. Virial analysis reveals that Fe-BTC has enhanced interaction strength with guest molecules compared to MIL‑100. Most notably, we observe striking discrimination between the adsorption of C3H6 and C3H8 in Fe‑BTC, with over a twofold increase in the amount of C3H6 being adsorbed than C3H8. Thermodynamic selectivity towards a range of industrially relevant binary mixtures is probed using ideal adsorbed solution theory (IAST). Together, this suggests the disordered material may possess powerful separation capabilities that are rare even amongst crystalline frameworks.</div>

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Temperature dependence of adsorption hysteresis in flexible metal organic frameworks

Communications Chemistry ◽

10.1038/s42004-020-00429-3 ◽

2020 ◽

Vol 3 (1) ◽

Cited By ~ 1

Author(s):

Shamsur Rahman ◽

Arash Arami-Niya ◽

Xiaoxian Yang ◽

Gongkui Xiao ◽

Gang (Kevin) Li ◽

...

Keyword(s):

Temperature Dependence ◽

Capillary Condensation ◽

Metal Organic Frameworks ◽

Sorption Isotherms ◽

Separation Performance ◽

Process Simulations ◽

Metal Organic ◽

Flexible Metal ◽

Pressure Swing ◽

External Stimuli

Abstract“Breathing” and “gating” are striking phenomena exhibited by flexible metal-organic frameworks (MOFs) in which their pore structures transform upon external stimuli. These effects are often associated with eminent steps and hysteresis in sorption isotherms. Despite significant mechanistic studies, the accurate description of stepped isotherms and hysteresis remains a barrier to the promised applications of flexible MOFs in molecular sieving, storage and sensing. Here, we investigate the temperature dependence of structural transformations in three flexible MOFs and present a new isotherm model to consistently analyse the transition pressures and step widths. The transition pressure reduces exponentially with decreasing temperature as does the degree of hysteresis (c.f. capillary condensation). The MOF structural transition enthalpies range from +6 to +31 kJ·mol−1 revealing that the adsorption-triggered transition is entropically driven. Pressure swing adsorption process simulations based on flexible MOFs that utilise the model reveal how isotherm hysteresis can affect separation performance.

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Assembly of Two Flexible Metal–Organic Frameworks with Stepwise Gas Adsorption and Highly Selective CO2 Adsorption

Crystal Growth & Design ◽

10.1021/cg500091k ◽

2014 ◽

Vol 14 (5) ◽

pp. 2375-2380 ◽

Cited By ~ 31

Author(s):

Jing Wang ◽

Jiahuan Luo ◽

Jun Zhao ◽

Dong-Sheng Li ◽

Guanghua Li ◽

...

Keyword(s):

Gas Adsorption ◽

Co2 Adsorption ◽

Metal Organic Frameworks ◽

Metal Organic ◽

Flexible Metal

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Integration of Fluorescent Functionality into Pressure Amplifying Metal-Organic Frameworks

10.26434/chemrxiv.14680335.v1 ◽

2021 ◽

Author(s):

Francesco Walenszus ◽

Jack D. Evans ◽

Volodymyr Bon ◽

Friedrich Schwotzer ◽

Irena Senkovska ◽

...

Keyword(s):

Structural Changes ◽

Gas Adsorption ◽

Metal Organic Frameworks ◽

Metal Exchange ◽

Limited Information ◽

X Ray Diffraction ◽

Metal Organic ◽

Synthetic Metal ◽

External Stimuli ◽

Highly Porous

The flexibility of soft porous crystals, i.e., their ability to respond to external stimuli with structural changes, is one of the most fascinating features of metal-organic frameworks. In addition to breathing and swelling phenomena of flexible MOFs, negative gas adsorption and pressure amplification is one of the more recent discoveries in this field, initially observed in the cubic DUT-49 framework. In recent years the structural contraction was monitored by physisorption, X‑ray diffraction, NMR and EPR techniques, providing only limited information about the electronic structure of the ligand. In this work we designed a new ligand with a fluorescent core in the linker backbone and synthesized three new MOFs, isoreticular to DUT-49, denoted as DUT‑140(M) (M - Cu, Co, Zn) crystalizing in space group. DUT‑140(Cu) can be desolvated and is highly porous with an accessible apparent surface area of 4870 m2g-1 and a pore volume of 2.59 cm3g-1. Furthermore, it shows flexibility and NGA upon adsorption of subcritical gases. DUT-140(Zn), synthesized using post-synthetic metal exchange, could only be studied with guests in the pores. In addition to the investigation of the adsorption behavior of DUT-140(Cu) spectroscopic and computational methods were used to study the light absorption properties.

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Thermally Activated Dynamic Gating Underlies Higher Gas Adsorption at Higher Temperatures in Metal Organic Frameworks

Journal of Materials Chemistry A ◽

10.1039/d1ta06562a ◽

2021 ◽

Author(s):

Abhishek Sharma ◽

Nimish Dwarkanath ◽

Sundaram Balasubramanian

Keyword(s):

Gas Adsorption ◽

Metal Organic Frameworks ◽

Computational Tools ◽

Thermally Activated ◽

Complementary Role ◽

Metal Organic ◽

Flexible Metal

In unraveling the mechanism of kinetically governed gas adsorption in flexible metal-organic frameworks (MOFs), the careful employment of advanced computational tools can play a vital complementary role to experiments. Herein,...

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Modeling Gas Adsorption in Flexible Metal–Organic Frameworks via Hybrid Monte Carlo/Molecular Dynamics Schemes

Advanced Theory and Simulations ◽

10.1002/adts.201800177 ◽

2019 ◽

Vol 2 (4) ◽

pp. 1800177 ◽

Cited By ~ 13

Author(s):

Sven M. J. Rogge ◽

Ruben Goeminne ◽

Ruben Demuynck ◽

Juan José Gutiérrez‐Sevillano ◽

Steven Vandenbrande ◽

...

Keyword(s):

Molecular Dynamics ◽

Monte Carlo ◽

Gas Adsorption ◽

Metal Organic Frameworks ◽

Hybrid Monte Carlo ◽

Metal Organic ◽

Flexible Metal

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Selective Gas Adsorption in the Flexible Metal-Organic Frameworks Cu(BDTri)L (L=DMF, DEF)

Chemistry - A European Journal ◽

10.1002/chem.201000053 ◽

2010 ◽

Vol 16 (20) ◽

pp. 5902-5908 ◽

Cited By ~ 101

Author(s):

Aude Demessence ◽

Jeffrey R. Long

Keyword(s):

Gas Adsorption ◽

Metal Organic Frameworks ◽

Metal Organic ◽

Flexible Metal

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Gas Adsorption Selectivity in Topologically Disordered Metal–Organic Frameworks

10.26434/chemrxiv.14680353.v1 ◽

2021 ◽

Author(s):

Adam Sapnik ◽

Christopher W. Ashling ◽

Lauren K. Macreadie ◽

Seok J. Lee ◽

Tim Johnson ◽

...

Keyword(s):

Gas Adsorption ◽

Metal Organic Frameworks ◽

Interaction Strength ◽

Functional Materials ◽

Adsorption Selectivity ◽

Guest Molecules ◽

Sorption Behaviour ◽

Ideal Adsorbed Solution Theory ◽

Industrial Gases ◽

Metal Organic

<div>Disordered metal–organic frameworks are emerging as an attractive class of functional materials, however their applications in gas storage and separation have yet to be fully explored. Here, we investigate gas adsorption in the topologically disordered Fe-BTC framework and its crystalline counterpart, MIL‑100. Despite their similar chemistry and local structure, they exhibit very different sorption behaviour towards a range of industrial gases, noble gases and hydrocarbons. Virial analysis reveals that Fe-BTC has enhanced interaction strength with guest molecules compared to MIL‑100. Most notably, we observe striking discrimination between the adsorption of C3H6 and C3H8 in Fe‑BTC, with over a twofold increase in the amount of C3H6 being adsorbed than C3H8. Thermodynamic selectivity towards a range of industrially relevant binary mixtures is probed using ideal adsorbed solution theory (IAST). Together, this suggests the disordered material may possess powerful separation capabilities that are rare even amongst crystalline frameworks.</div>

Download Full-text

Integration of Fluorescent Functionality into Pressure Amplifying Metal-Organic Frameworks

10.26434/chemrxiv.14680335 ◽

2021 ◽

Author(s):

Francesco Walenszus ◽

Jack D. Evans ◽

Volodymyr Bon ◽

Friedrich Schwotzer ◽

Irena Senkovska ◽

...

Keyword(s):

Structural Changes ◽

Gas Adsorption ◽

Metal Organic Frameworks ◽

Metal Exchange ◽

Limited Information ◽

X Ray Diffraction ◽

Metal Organic ◽

Synthetic Metal ◽

External Stimuli ◽

Highly Porous

The flexibility of soft porous crystals, i.e., their ability to respond to external stimuli with structural changes, is one of the most fascinating features of metal-organic frameworks. In addition to breathing and swelling phenomena of flexible MOFs, negative gas adsorption and pressure amplification is one of the more recent discoveries in this field, initially observed in the cubic DUT-49 framework. In recent years the structural contraction was monitored by physisorption, X‑ray diffraction, NMR and EPR techniques, providing only limited information about the electronic structure of the ligand. In this work we designed a new ligand with a fluorescent core in the linker backbone and synthesized three new MOFs, isoreticular to DUT-49, denoted as DUT‑140(M) (M - Cu, Co, Zn) crystalizing in space group. DUT‑140(Cu) can be desolvated and is highly porous with an accessible apparent surface area of 4870 m2g-1 and a pore volume of 2.59 cm3g-1. Furthermore, it shows flexibility and NGA upon adsorption of subcritical gases. DUT-140(Zn), synthesized using post-synthetic metal exchange, could only be studied with guests in the pores. In addition to the investigation of the adsorption behavior of DUT-140(Cu) spectroscopic and computational methods were used to study the light absorption properties.

Download Full-text